1. Field of Technology
The present invention generally relates to a microfilming camera assembly and, more particularly, to an illuminator used therein for illuminating a document to be microfilmed.
2. Description of the Prior Art
The microfilming camera assembly is now made available generally in two types. One is referred to as a "flatbed" type, or possibly an overhead type, wherein, while a photographic camera is mounted overhead the document support for the support thereon of a document to be microfilmed, an illuminator lamp is supported on each side of the document support for illuminating the document placed on the document support, such as disclosed in, for example, U.S. Pat. Nos. 3,649,120 and 3,669,534. The other is referred to as an "Inverted-flatbed" type, or possibly a built-in type, wherein the illuminator lamp is supported on each side of the main mirror disposed beneath the transparent document support for deflecting the imagewise light, such as disclosed in, for example, U.S. Pat. Nos. 3,972,619 and 3,697,176.
The "flatbed", or overhead, type renders the microfilming camera assembly as a whole to be bulky, whereas the "Inverted-flatbed", or built-in, type requires an optical path of increased distance for minimizing an irregular illumination, the increased distance of the optical path in turn rendering the camera assembly as a whole to be bulky.
In any event, in both of these types, neither design nor device have hitherto been developed for maximizing the efficiency of use of light emanating from the illuminator lamps. Also, another problem arises that, if the illuminator optical path is shortened, the distribution of light used to illuminate the document to be microfilmed tends to become irregular.